$ { {-4} \times \left[\begin{array}{rr}{-1} & {1} \\ {4} & {2} \\ {4} & {0}\end{array}\right] = {?} } $
Explanation: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{-4}\times{-1} & {-4}\times{1} \\ {-4}\times{4} & {-4}\times{2} \\ {-4}\times{4} & {-4}\times{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{4} & {-4} \\ {-16} & {-8} \\ {-16} & {0}\end{array}\right]}$